1. Field of the Invention
This invention relates to an improved anchoring arrangement for use in conjunction with cavity walls having a backup wall and a facing wall. More particularly, the invention relates to construction accessory devices, namely, high-strength anchors and anchoring systems. The anchors are specially configured to maintain a high strength interconnection with a truss or ladder reinforcement. The ribbon loop anchors of this invention resist deformation and interconnect with a variety of veneer ties. The invention is applicable to structures having a facing wall of brick or stone in combination with a backup wall of masonry block, seismic-resistant structures, and to cavity walls requiring thermal isolation.
2. Description of the Prior Art
In the past, investigations relating to the effects of various forces, particularly lateral forces, upon brick veneer masonry construction demonstrated the advantages of having high-strength wire anchoring components embedded in the bed joints of anchored cavity walls, such as facing brick or stone veneer.
With the promulgation of standards requiring higher strength components and concomitantly the expansion of the cavity of the wall to accommodate increased insulation, the technical demands on the anchoring systems have changed dramatically. Such changes, when analyzed, have resulted in wall structures or building envelopes wherein the forces applied at the interconnection between the wall anchor and the veneer tie increase result in added stress to the anchor interconnection joints. Prior tests have shown that failure of anchoring systems frequently occur at the juncture between the anchor receptor portion and the veneer tie. Deformation, including possible cracking, of the anchor receptor portion may result from the increased stresses thereby causing misalignment, which impacts on the structural integrity of the cavity wall. This invention addresses the need for a high-strength anchor and anchor receptor portion suitable for use with a ladder or truss wall reinforcement that provides a strong veneer tie-to-receptor connection.
Early in the development of high-strength anchoring systems a prior patent, namely U.S. Pat. No. 4,875,319 ('319), to Ronald P. Hohmann, in which a molded plastic clip is described as tying together reinforcing wire and a veneer tie was disclosed. The assignee of '319, Hohmann & Barnard, Inc., now a MiTek-Berkshire Hathaway company, successfully commercialized the device under the SeismiClip® trademark. For many years the white plastic clip tying together the veneer anchor and the reinforcement wire in the outer wythe has been a familiar item in commercial seismic-zone buildings. A later development by Hohmann & Barnard improving on the seismic structure includes a swaged back leg as shown in the inventor's patent, U.S. Pat. No. 7,325,366. The combination item reduces the number of “bits and pieces” brought to the job site and simplifies installation.
Recently, there have been significant shifts in public sector building specifications which have resulted in architects and architectural engineers requiring larger and larger cavities in the exterior cavity walls of public buildings. These requirements are imposed without corresponding decreases in wind shear and seismic resistance levels or increases in mortar bed joint height. Thus, the wall anchors needed are restricted to occupying the same ⅜-inch bed joint height in the inner and outer wythes. Thus, the veneer facing material is tied down over a span of two or more times that which had previously been experienced. Exemplary of the public sector building specification is that of the Energy Code Requirement, Boston, Mass. (See Chapter 13 of 780 CMR, Seventh Edition). This Code sets forth insulation R-values well in excess of prior editions and evokes an engineering response opting for thicker insulation and correspondingly larger cavities.
Besides earthquake protection requiring high-strength anchoring systems, the failure of several high-rise buildings to withstand wind and other lateral forces has resulted in the promulgation of more stringent Uniform Building Code provisions. This high-strength anchor is a partial response thereto. The inventor's related anchoring system products have become widely accepted in the industry.
In the past, the use of wire formatives have been limited by the mortar layer thicknesses which, in turn are dictated either by the new building specifications or by pre-existing conditions, e.g., matching during renovations or additions the existing mortar layer thickness. While arguments have been made for increasing the number of the fine-wire anchors per unit area of the facing layer, architects and architectural engineers have favored wire formative anchors of sturdier wire. On the other hand, contractors find that heavy wire anchors, with diameters approaching the mortar layer height specification, frequently result in misalignment. This led to the low-profile wall anchors of the inventors hereof as described in U.S. Pat. No. 6,279,283.
The following patents are believed to be relevant and are disclosed as being known to the inventor hereof:
U.S. Pat. No.InventorIssue Date3,377,764StorchApr. 16, 19684,021,990SchwalbergMay 10, 19774,373,314AllanFeb. 15, 19834,473,984LopezOct. 2, 19844,598,518HohmannJul. 8, 19864,869,038CataniSep. 26, 19894,875,319HohmannOct. 24, 19895,454,200HohmannOct. 3, 19956,668,505Hohmann et al.Dec. 30, 20036,789,365Hohmann et al.Sep. 14, 20046,851,239Hohmann et al.Feb. 8, 20057,017,318HohmannMar. 28, 20067,325,366HohmannFeb. 5, 2008
It is noted that these devices are generally descriptive of wire-to-wire anchors and wall ties and have various cooperative functional relationships with straight wire runs embedded in the interior and/or exterior wythe.
U.S. Pat. No. 3,377,764—D. Storch—Issued Apr. 16, 1968 discloses a bent wire, tie-type anchor for embedment in a facing exterior wythe engaging with a loop attached to a straight wire run in a backup interior wythe.
U.S. Pat. No. 4,021,990—B. J. Schwalberg—Issued May 10, 1977 discloses a dry wall construction system for anchoring a facing veneer to wallboard/metal stud construction with a pronged sheet metal anchor. Like Storch '764, the wall tie is embedded in the exterior wythe and is not attached to a straight wire run.
U.S. Pat. No. 4,373,314—J. A. Allan—Issued Feb. 15, 1983 discloses a vertical angle iron with one leg adapted for attachment to a stud; and the other having elongated slots to accommodate wall ties. Insulation is applied between projecting vertical legs of adjacent angle irons with slots being spaced away from the stud to avoid the insulation.
U.S. Pat. No. 4,473,984—Lopez—Issued Oct. 2, 1984 discloses a curtain-wall masonry anchor system wherein a wall tie is attached to the inner wythe by a self-tapping screw to a metal stud and to the outer wythe by embedment in a corresponding bed joint. The stud is applied through a hole cut into the insulation.
U.S. Pat. No. 4,598,518—R. Hohmann—Issued Jul. 7, 1986 discloses a dry wall construction system with wallboard attached to the face of studs which, in turn, are attached to an inner masonry wythe. Insulation is disposed between the webs of adjacent studs.
U.S. Pat. No. 4,869,038—M. J. Catani—Issued Sep. 26, 1989 discloses a veneer wall anchor system having in the interior wythe a truss-type anchor, and horizontal sheet metal extensions. The extensions are interlocked with bent wire pintle-type wall ties that are embedded within the exterior wythe.
U.S. Pat. No. 4,875,319—R. Hohmann—Issued Oct. 24, 1989 discloses a seismic construction system for anchoring a facing veneer to wallboard/metal stud construction with a pronged sheet metal anchor. Wall tie is distinguished over that of Schwalberg '990 and is clipped onto a straight wire run.
U.S. Pat. No. 5,454,200—R. Hohmann—Issued Oct. 1995 discloses a facing anchor with straight wire run and mounted along the exterior wythe to receive the open end of wire wall tie with each leg thereof being placed adjacent one side of reinforcement wire. As the eye wires hereof have scaled eyelets or loops and the open ends of the wall ties are sealed in the joints of the exterior wythes, a positive interengagement results.
U.S. Pat. No. 6,668,505—Hohmann et al.—Issued Dec. 30, 2003 discloses high-span and high-strength anchors and reinforcement devices for cavity walls combined with interlocking veneer ties are described which utilize reinforcing wire and wire formatives to form facing anchors, truss or ladder reinforcements, and wall anchors providing wire-to-wire connections therebetween.
U.S. Pat. No. 6,789,365—R. Hohmann et al.—Issued Sep. 14, 2004 discloses side-welded anchor and reinforcement devices for a cavity wall. The devices are combined with interlocking veneer anchors, and with reinforcements to form unique anchoring systems. The components of each system are structured from reinforcing wire and wire formatives.
U.S. Pat. No. 6,851,239—Hohmann et al.—Issued Feb. 8, 2005 discloses a high-span anchoring system described for a cavity wall incorporating a wall reinforcement combined with a wall tie which together serve a wall construct having a larger-than-normal cavity. Further the various embodiments combine wire formatives which are compressively reduced in height by the cold-working thereof. Among the embodiments is a veneer anchoring system with a low-profile wall tie for use in a heavily insulated wall.
U.S. Pat. No. 7,017,318—Hohmann—Issued Mar. 28, 2006 discloses an anchoring system with low-profile wall ties in which insertion portions of the wall anchor and the veneer anchor are compressively reduced in height.
U.S. Pat. No. 7,325,366—Hohmann—Issued Feb. 5, 2008 discloses snap-in veneer ties for a seismic construction system in cooperation with low-profile, high-span wall anchors.
None of the above anchors or anchoring systems provide an anchoring system having a high-strength anchor and ribbon loop receptor for fulfilling the need for enhanced compressive and tensile properties. This invention relates to an improved anchoring arrangement for use in conjunction with cavity walls and meets the heretofore unmet need described above.